Not clear what you're specifically talking about. Whether the strokes are "smooth" depends on the specific Art Brush you are using.

The Scale Strokes and Effects setting is buried in the Transformation palette's flyout menu and in General Prefs. That controls whether stroke weights (including those of Brush strokes) scale when the paths are scaled.

If you're talking about those blobs that look like ink blotches at sharp bends, that aberation occurs sometimes depending again on the artwork used to define the Art Brush and the shapes of the paths to which the Brush is applied.

Can't tell what you've got in your screenshot, because the paths are not selected. Also, post an image of the Brush itself.

I just am baffled by this I am certain you guys are right but I cannot for the love of me make this bug manifest itself when scaling an object that was created with the brush tool with a calligraphic brush…

so what am I missing here is a video the only thing I did not try was scaling with an Transform effect and the transform panel.

Look in the Appearance panel and double-click the Zig-Zag effects line to open the dialog. Using 0 offset and 100 points per segment does smooth out the line.

Yes, but not the real point, Larry. The question is, how many guys do you know who would look at the OP's blobby problem and say to himself, "Oh, why don't we just apply the Zig-Zag effect on this? We'll set a low offset and a high points per segment... yeah that should do it."

I know none. Except Kurt. His solution seems as likely as calling in live to the healthcare summit in Washington, DC and asking the Minority Whip if he knows how to work out the kinks in the OP's calligraphic brush.

As an irrelevancy, I actually LIKE the style of the OP's artwork... reminds me of a leaky fountain pen.

I would never in a million years have thought to apply the effects and do the zig zag thing.. and it did work, sort of, but repeating this process on every line is time consuming and it did not work on all parts.

Can I just clarify - Am I having this problem because I used a calligraphy brush?

If I selected a different brush would I not need to apply the Zig Zag filter every time?

Do not use a brush just use a stroke but since you have a brush applied to the stroke you have to give it a stroke of none, so you can see what you are doing, then in the appearance panel from the fly out give it a new stroke.

The default stroke will be applied of black, 1pt it will be an even line you can now delete the previous stroke. If the new stroke is too thick or thin you can easily change it in either the stroke panel or the appearance panel.

Save the file.

You can make an artbrush as well

and you might prefer to use the pen tool for drawing such illustrations. Many users do.